The invention is directed to a spatial disorientation trainer-flight simulator wherein a cockpit is gimballed on three independently controlled axes at the end of an arm coupled to a planetary hub. The hub is capable of rotating so as to exert centripetal forces in the order of 2g's on the pilot. Each of the gimbal axes is separately controlled by high torque direct drive motors so as to obtain smooth, continuous changes in speed from a sub-threshold speed range (0.5.degree./sec-5.degree./sec) to speeds of 200.degree./sec.
The invention simulates various spatial disorientation effects experienced in high performance jet aircraft, including somatogyral and somatogravic illusions, the Coriolis effect, "the leans" and other disorienting effects. The somatogyral and somatogravic illusions can be sustained indefinitely. The invention comprises a dynamic computer controlled system which can include the pilot. Vestibular illusions are produced by computer control of the gimbal and planetary axes. The conditions may be changed instantaneously by an operator, by the pilot or by stored program. Flight instruments are controlled to indicate the simulated flight conditions. The pilot is able to control the gimbal axes so as to "fly out" of various disorienting effects.
Various spatial disorientation devices and flight simulators are known in the art. For example, U.S. Pat. No. 3,436,841 discloses a portable spatial disorientation device which can be used as a trainer. The device includes a cockpit rotatable about a planetary hub. The cockpit is connected by a frame to the hub. The frame is mounted on rollers which travel on a circular track. The frame supports a motor which is coupled by a chain drive to one of the wheels so as to initiate planetary motion about the hub. The cockpit is mounted on a platform rotatable 360.degree. in yaw, from 0-10 rpm (60.degree./sec). The platform can be rolled hydraulicly to a fixed position, plus or minus 15.degree. about the roll axis. The roll position must be held during yaw rotation and during planetary rotation.
The cockpit is provided with a throttle, joy stick and yaw pedals. An attitude indicator is provided in the forward part of the cockpit. The cockpit motion is controlled by an operator, not the pilot. The pilot's responses (in operating the throttle, joy stick and pedals) are merely recorded. The hub is provided with slip rings to make one-way power connections to the cockpit motors. There is no bidirectional data communication through the slip rings.
U.S. Pat. No. 3,281,962 discloses an hydraulicly powered flight simulator. A single hydraulic actuator is employed for vertical translation; another for roll; another for yaw; and two more for pitch. A cylinder connected between the cockpit and a pitch frame provides the roll motion. A yaw guide or track (mounted on the front of the pitch frame) and a hydraulic actuator provide yaw motion. Pitch motion is provided by a pair of actuators coupled between an acceleration frame and the pitch frame. The actuators are controlled by a programmed computer. Apparently, the pilot is not incorporated in the control loop, i.e., the pilot cannot control the cockpit motion.
U.S. Pat. No. 2,930,144 discloses a flight trainer which is operated based on perceptible impulses of motion. A pitch motor is geared to a splined pitch shaft journaled in an outer gimbal frame. An inner gimbal frame is provided with a splined hug which meshes with the pitch shaft. A cylinder is provided to laterally displace the inner frame over short distances. The cockpit is mounted on a splined roll shaft journaled in the inner gimbal frame. The roll shaft is gear coupled to and driven by a motor. A cylinder is also connected between the inner gimbal frame and cockpit to displace the cockpit fore/aft over short distances. Slip rings and flexible cabling may be employed to connect the cockpit motors. Apparently, the pilot is not incorporated in the control loop.
U.S. Pat. No. 3,196,557 discloses a centrifuge mounted motion simulator. A central concrete pylon pivotably supports one end of a truss type centrifuge arm. An elevator tower is coupled to the other end of the arm. The tower includes trolly wheels which ride on a circular railroad track. A vertically displaceable elevator cage is mounted on the tower. The cockpit is gimballed on the cage. The centrifuge arm is driven by an endless cable entrained on the circular track and wound on motor driven drums at the pylon. The yaw frame is gimballed on the cage and rotated by a motor which is coupled to the frame by means of a chain drive. The pitch frame is gimballed to the yaw frame and is rotated by a chain drive coupled to the yaw frame. The cockpit is gimballed on the pitch frame for roll movement by a motor which is mounted on the pitch frame and chain coupled to the cockpit. The motors are operated by a programmed computer. Apparently, the pilot is not in the control loop.
U.S. Pat. Nos. Re. 27,051 and 2,687,580 disclose devices wherein the pilot exercises control over capsule motion, but in response to disorientation effects produced by computer generated signals. Patent Re. 27,051 discloses a linear actuator dynamic acceleration simulator. The device provides movement in six degrees of freedom, three linear and three rotational (pitch, roll and yaw). The device comprises an hexagonal shaped platform supported by six linear actuators which extend between the platform and the base. The actuators are hydraulicly extended or retracted separately or in combination so as to provide movement in the various degrees of freedom. The actuators are coupled by a mechanical analog conversion system including a mechanical model and mechanical-to-electrical transducers. The system is driven by a computer in response to pilot signals from the capsule.
U.S. Pat. No. 2,687,580 discloses a flight trainer and simulator. The simulator includes a cockpit which is gimballed for pitch and roll only. Servo systems compute the pitch and roll angles for simulating the desired effect in response to pilot control. The servo systems determine air speed, yaw rate, yaw, pitch rate, pitch, angle of attack and side-slip. The pitch movement is actuated by a rotary transformer coupled by a gear reduction to a servo motor, and the pitch of the cockpit is varied by mechanical connection between the servo motor shaft and the cockpit pitch axis. The roll of the cockpit is similarly controlled.
U.S. Pat. No. 3,829,988 is directed to a flight simulator wherein a cockpit is mounted for pitch and roll movement only. There is no yaw motion. The pilot is not incorporated in a control loop.
U.S. Pat. No. 3,340,619 discloses a pilot testing apparatus wherein a rectangular nacelle mounted on a telescopic arm is guided along a cushioned elliptical track. The nacelle includes a gimballed cockpit. An electric motor is coupled by worm gears to the gimbal frames to initiate rotation with respect to any of the three gimbal axes.
U.S. Pat. No. 3,221,419 discloss a flight simulator which simulates true linear acceleration, accounting for the Coriolis effect. The gimbal frames are rotated by two motors.
A concise summary of the various disorienting effects and illusions experienced during flight is contained in Gillingham, K. et. al., "Design Criteria For The Spatial Orientation Trainer" (USAF School of Aerospace Medicine July 6, 1967) at pages 5-10 and Gillingham, K., "Advanced Spatial Disorientation Training Concepts", Aeromedical Review (USAF School of Aerospace Medicine December 1974) at pages 5-17, incorporated herein by reference. A U.S. Air Force spatial orientation trainer is described therein as permitting responsive control by the pilot to oculographic, Coriolos and oculogyral effects.
Aviation Week & Technology (Sept. 15, 1975) discloses an inertial guidance motion simulator which uses direct drive, high torque dc motors to simulate three axes of guidance system flight motion.
An object of the present invention is to provide a spatial disorientation trainer and flight simulator wherein the pilot is "in the loop".
Another object of the invention is to provide a spatial disorientation trainer wherein the pilot is subjected to a centripetal force as high as 2g's so as to enable the pilot to practice the "L1" or "M1" breathing maneuver.
Another object of the invention is to provide unlimited yaw motion at speeds as high as 200.degree./sec so as to simulate the "flat spin" effect of a jet aircraft.
Another object of the invention is to provide a sustained centripetal force approaching 2g's whereby the somatogravic illusion may be created.
Another object of the invention is to provide sub-threshold pitch, roll and yaw motion speeds so as to create the disorientation effect known as "the leans".
Another object of the invention is to provide both power and bidirectional data transfer between the planetary axis and (cockpit) yaw axis without limiting rotation about either axis.
Other objects and advantages of the invention appear hereinafter.